Form over function: the development of foods by physicists that could cut down cravings

1 November 2016

In this month’s Physics World, biophysicist Cait MacPhee discusses how functional foods developed by soft-matter physicists could help solve the global obesity crisis.

The world is facing an obesity epidemic; more adults in the world are now classified as obese compared to those who are underweight, and obesity rates have tripled for men and doubled for women since 1975.

Weight gain is caused by a number of factors, but the way in which our body reacts when eating different foods, and then notifies us when to stop, is one factor that physicists may be able to manipulate.

The sensation of satiety, or feeling full, is triggered by a number of hormonal cues derived from digesting food and physicists may be able to re-engineer the food we eat to increase these triggers and make us feel fuller for longer.

In her article Hungry for solutions, available in this month’s Physics World, Cait MacPhee explains: “When we eat, our bodies respond with an incredibly complex hormonal process, one that takes into account not just what’s on our plates that day, but also what we have eaten in the past, and how much of it.”

“Unfortunately, the outcome of this response is that, essentially, we train our bodies to get fat – and it doesn’t seem to be easy to train them to become thin again.”

Functional foods are those that are engineered to deliver more than just the usual nutritional content, and they already populate our supermarket shelves and kitchen cupboards: eggs with added omega-3 fatty acids; bread and milk enriched with extra vitamins; and foods that are lactose- or gluten-free are all so-called functional foods that many of us eat every day.

However, the creation of new functional foods draws on the skills of soft-matter physicists – those who study the science of complex fluids and dispersed components within – to understand the structure of these foods and how to modify them without changing or ruining the taste and texture of the finished product.

Explains McPhee: “Food physics offers the opportunity to get around this dilemma by creating new products that mimic the texture and taste of unhealthy but well-loved foods, with added components that, when released in a controlled fashion at specific sites within the body, improve our feeling of satisfaction.

“Clever food processing also offers the potential for decreasing the amount of salt and sugar in processed foods, at least where they are added for reasons other than taste or nutrition.”

For the UK, where food manufacturing is the biggest sector in industry, the demand for soft-matter physics is increasingly pressing to help solve challenges like these. Concludes McPhee: “Perhaps clever physics may yet help us stem the developed world’s obesity crisis.”